Don't Tempt Me
by cadlg7
Summary: Dean, a highly respected assassin amongst the demons, was given the mission to get rid of Castiel Novak, the top killer compared to other angels. He was not expected to have a steamy one night stand with him. More importantly, they weren't supposed to fall for each other. Angel! Cas x Demon! Dean. Slight Mr. & Mrs. Smith AU. Rated M for later chapters.
1. You Shook Me

**You Shook Me**

_**You Shook Me All Night Long by AC/DC**_

_He was a fast Machine, she kept his motor clean_

_He was best damn man I had ever seen_

_He had the sightless eyes, telling me no lies_

_Knocking me out with those American thighs_

_Taking more than his share_

_Had me fighting for air_

_He told me to come but I was already there_

By the way the sunlight bothered him when the door to his hotel room opened, Dean could tell that it was somewhere between one and two in the afternoon.

One of the few perks of being a demon is that the hangovers didn't last as long as they did back when he was human. But even then, a headache pill would've been nice. It really would've.

He rubbed his head and looked sideways. He didn't expect for his one-nighter to stay around, it was expected for them to leave. He turned to the clock to check the time, it was eleven-thirty, much earlier than Dean had assumed.

It was no surprise for Dean to not remember much about the night before, but the more thought he gave it, the clearer the images became. For example, he'd slept with a man. He remembered flirting with him at the nightclub he'd gone to out of pure boredom, not expecting to get lucky that night, complimenting his eyes, his gorgeous, bright blue eyes.

The memories got better when he began recalling the sex. Damn, it was good. There was everything from hair pulling to the bittersweet sensation of the back scratches the man had left on him. He remembered the moaning, oh, the loud moaning that told Dean that he'd done an excellent job at pleasing his submissive.

_Dean, please, I'm…so close…yes, ngh, like that…_ Mmmm, he enjoyed having him beg like that, have his teeth bite down his lip to hold back a loud moan that'd wake up the people from the room next to theirs. He didn't know he could be so dirty. _Dean, I'm…oh, yes…yes!_ The blissful feeling of having his hands search for a spot on the bed that he could grip on tightly to as he climaxed.

_There were also wings_. Long, beautiful, white wings that seemed to be the weak spot of the man he'd slept with. He could tell because when Dean held on to them, the man's moans of pleasure only became louder the more he dug his fingers into his fluffy feathers. Could Dean have possibly…?

Dean ran his fingers through his dark blonde locks, "Holy shit, I slept with an angel." He fisted his hair, "_Fuck_, I slept with an angel!" He'd screwed up. He'd done the prohibited, the rare, Dean, a demon, had fucked an angel.

He sat up and threw the covers to the side. He reached for his black shirt and faded jeans to get dressed and get out of there as soon as he could.

That's when he noticed the tanned trench coat on top of the mini fridge. That definitively wasn't his. The man could come back at any moment if he didn't hurry.

He picked up his jacket and checked the pockets for his car keys. It was empty. Did he lose them? Were they dropped somewhere? Dean walked to the curtains and peeked through the window. His Impala was gone.

Could it be that…that the man took it?

The fucking mystery man took his car!

But who would've known, the guy didn't seem that the other night when Dean was trying to seduce him to get what he wanted. Sure, the way he moved those hips on the dance floor, perfectly matching the rhythm of Usher's song, driving Dean insane, didn't make the angel seem as innocent as he appeared—neither did the sex of that same night but, you know, details— but he never thought of him as a thief.

Suddenly, he felt his phone vibrate in his jeans. It was a text from his boss, Crowley, which he had received the day before but never opened. **Name of your mission: Castiel Novak. Age: 28. ANGEL. **

_Fuck, could this man be? Could he be Castiel?_

Before he could reply to the message, he heard the door unlock, making Dean drop his jacket out of surprise. He didn't think he'd be back.

The door opened and a very handsome young man with dark brown hair the same blue eyes that Dean remembered well, walked in holding a small paper bag and two cups of hot coffee. "Hey, you're up." The man grinned, revealing his perfect white teeth. He wore black jeans and a dark gray Led Zeppelin shirt that really hid the lean but muscular figure that Dean had admired during sex.

Dean forced a smile, "Yeah."

"Coffee?" He offered him a cup.

"No, no thank you." He pointed at the bag, "Although, I could use some of whatever it is you have there."

"Oh, this?" He opened the bag and pulled out a wrapped up muffin and a plastic container that caught Dean's eyes immediately, "I have a chocolate chip muffin for me and…well, I didn't know what you'd like so I got you pumpkin pie." He stepped forward to give the slice of pie he had been eyeing since he took it out, "Also, I apologize for taking your car." The man grabbed the keys from his jean's pocket and gave them to Dean.

"It's fine. All is forgiven since you got me pie. Not many people can guess I like pie."

"It was lucky." Castiel mumbled.

"Yeah, so, uh…what was your name again? I was pretty drunk last night so I'm sorry if I don't…"

"My name's Castiel."

_Shit, shit, shit!_

"Ah," That was all Dean managed to say. That was all he _could_ say.

He couldn't believe he slept with his mission. How could he not have guessed? It was logical. Working for demons to kills anything or anyone that got in their way, this including the angels especially.

"Were you planning on leaving?" Castiel asked, snapping Dean out of his thoughts.

"I have to."

Castiel chuckled, "You don't exactly have to, you just _want_ to."

Dean nodded and agreed to what Castiel had said, making the man's smile fade away quickly, "I'm sorry."

"It's alright, I suppose, I just thought maybe we could set our obvious differences aside," Oh, Castiel was one of those people that enjoyed talking about feeling and was into that 'getting to know each other' crap, "And just kind of get to know each other a little." There it was.

"I'm not the chick flick type, man."

"But you are into kinky." Castiel mumbled again, this time Dean did hear him.

If by kinky, Castiel meant bondage, then yes, Dean was really into that type of stuff.

But Castiel didn't seem to mind when Dean used his belt to tie Castiel's hands together and his blue tie to cover his eyes (he took both of them off later into their session) last night. In fact he seemed to enjoy it more than Dean.

"You liked it though." Dean said.

Castiel blushed. He knew it was inappropriate for an angel to be into that type of stuff but how could he have said no to a hot demon like Dean. "I can't say I didn't. I'd be lying."

"Well, I'm glad I successfully fulfilled your pleasures, but I have to get going."

"Dean," It was the first time Castiel had said Dean's name since the other night and Dean had to admit that he liked how it sounded when he'd said it when he wasn't pleading or moaning. For a thick moment, Castiel considered in asking him to lunch, into taking him out somewhere and get to know the humanity the remained in him. He knew Dean wasn't a human possessed by a demon; he was a demon that'd kept his body. "You know what, never mind." Dean was the typical guy he'd crossed paths frequently since he'd come down to Earth. He was no different than the other men that raised his hopes only to drop them after they got what they wanted.

Dean saw what Castiel wanted. If he accepted, maybe his mission could be much simpler, take him out during the first chance he got, it's not like Castiel was any more difficult than any angel Dean had encountered before, and he'd probably be easier.

"Are you leaving, then?" Castiel asked.

"Yes."

"It was nice meeting you, Dean…and I had a great time." Castiel stretched his hand to shake it. Yeah, he really did have a great time with Dean. He'd never had sex like that before and if he were given the opportunity to have it again, he'd take it. He wouldn't mind feeling Dean's hands all over him again, hearing his dirty talk.

Dean, took Castiel's hand, he ignored the electric feeling that passed through him when he touched the other man's fingers, and shook his hand. If only Castiel knew what was coming to him.

But Castiel did know.


	2. Love Me Again

**Love Me Again**

"_**Love Me Again" by John Newman**_

_Know I've done wrong,_

_Left your heart torn_

_Is that what devils do?_

_Took you so low,_

_Where only fools go_

_I shook the angel in you…/_

_/…Can you love me again?_

Crowley knew there was something wrong with Dean the moment he saw him walk in into his office. Sure, he was dressed for work, a black shirt and black cargo pants with combat boots of the same color, but it was the way that Dean avoided his gaze when he walked in that he knew something was off.

"Dean?" He asked, "Is there anything you'd like?"

He took a step forward and dropped a manila folder on his desk, "His name is Castiel Novak. That's all you gave me. Sam had to do the research for you."

"You act as if you weren't used to this." It was true. Dean should've been used to Crowley just giving names and their classification, he understand why he was so bothered about it now.

"I've asked you to stop giving me angels."

"You're the best one in the business for that, squirrel."

"There's better killers…Meg is one."

"Meg is sloppy. Sure, she gets the job done but she leaves trails behind that _I_ have to fix." Crowley leaned back on his chair, "What does it matter anyway? You never complain about your missions before, why are you doing it now?"

Dean blushed and he looked away, luckily for him, Crowley didn't see it. He could only imagine what Crowley would've said if he knew. Even he didn't understand why he was complaining about his target, he just fucked the guy, it's not like there was anything between them. Dean cleared his throat and turned to Crowley, "By when do you want him gone?"

"That's better…" Crowley gave him a satisfied smile, "Same time as always, forty eight hours."

"I'll get it done sooner than that."

"Don't disappoint me, Dean." Crowley didn't know why he was saying that, he knew how great Dean was at doing his job. "Don't disappoint _him_." By him, he meant the big guy, the one who trained all of the legendary demons, Dean included, the one who found Dean during his first days as a demon and gave him shelter when he thought he had nothing to go back to, _Cain_.

"Of course not." Dean forced a smile and walked out of Crowley's office. He reached for his phone in his pocket and dialed Sam's phone number.

Sam answered at the third ring, his voice sounded sleepy even though it was almost two in the afternoon, "Hello? Dean?"

"I'm going over."

"You were here yesterday. Am I missing something on that Castile guy or something?" He could hear Sam getting up.

"His name is Castiel and no you're not missing anything but I need to talk to you about something."

Sam yawned, "Okay."

"I'll see you in half an hour."

"Half an hour."

**-.-.-.-.-.-**

Thirty minutes later, like he had said, Dean was at Sam's apartment, knocking on his door. Sam opened. His hair was wet. "What is it?"

"Something happened, Sammy."

"How bad is it?" Dean had become less expressing so Sam had more trouble with knowing how much Dean screwed up with something.

"It's not as bad as I'm making it seem." Dean ran his fingers through his hair only making him think of Castiel and how he constantly did that the night they slept together. "Well, it sort of is…?"

"What did you do?" More like, _who_ did he do…?

"Remember the guy you were asked to look up?"

Sam looked at Dean in confusion as he grabbed his coffee cup, "What of him? Did you kill him already? Were you even supposed to kill him?"

"Yeah, I'm supposed to kill him and all but…something happened."

"Dean, can you stop sugar-coating this and just tell me what happened." Sam leaned against the wall and drank from his coffee.

"The guy of the research…"

"Oh," He snapped his fingers as he tried to remember the guy's name. Three hours of looking up information and he still couldn't remember. "Cas-Castile!"

"Castiel," Dean corrected.

"Whatever. What about him?"

"Remember the one night stand I didn't want to talk about?"

It took Sam almost two minutes to put the pieces together. Now, Dean understood why Crowley called him Moose. When he finally understood what had happened, a big smile spread across his face. "No. Way. _Dean, you didn't_!" He laughed at his brother when his eyes gave away the answer that yes, _he did_.

"I didn't know, okay!"

Sam laughed, "How could you have not known? Doesn't Crowley give you the mission's name?" He had to settle down his cup of coffee to enjoy the momentary flashes of panic in his brother's expressions and movements.

"I didn't check my phone until after it happened."

"Wait," Sam tried to stop laughing but this was too much of a precious moment to let it pass. Even before he had quit hunting, this had to be the funniest thing he had ever heard. "Wasn't this guy also like an angel?"

Dean looked down a little embarrassed, "Yes."

"_Oh, my God_!" Sam was laughing at Dean's situation again, "You slept with your angelic mission!" Oh the irony.

"Hey, you're the last person to talk, remember Ruby, huh?" But even with that, Sam didn't stop laughing. Dean seriously couldn't see the funny in his case.

Sam, once again, tried to stop laughing, only so that he could ask, "So, tell me, who topped?"

"Oh, blow me Sam!"

"Ask Castiel, I'm sure he'd be up for it!" Sam said between laughter.

"Remind me to never come to you for my problems, asswipe."

"No, Dean, I'm sorry."

"Too late for sorry, douchebag."

**-.-.-.-.-**

**Castiel paced around the office, **his friend Balthazar leaning against his desk and their trainee, Samandriel, sitting on a cushioned chair, cleaning one of his guns. His hands ran through his hair in desperation, "I slept with the Demon Winchester, Balthazar." Castiel said, making Samandriel look up in surprise.

"Are you serious? Gross."

"Is there a reason for me to joke about something like this?"

"No…it's just…you're such a goodie-two-shoes that…well, I didn't think you'd sleep with Dean Demonchester."

"It was accident."

"How was it an accident, I'm sure that when he was fucking you—"

"_Balthazar_!" Castiel hissed.

"I'm sure you would've known when you got down to it with him."

"I've noticed that as angels, we tend to underestimate demons a lot. And it's because we do that, that nineteen of our men and women have been killed on task this month. They've figured a way to keep us from seeing their true form. I suppose that's what attracted me to Dean." How could he not fall for the guy either way? With green eyes like those…?

"What are you going to do now?" Samandriel placed his gun back in its case when he was done cleaning it.

"What I was asked to do." Castiel said, fixing his long beige trench coat. "I'm going to kill him."

"Does he know about you?"

"By now, I'm sure he does." He shook his head, trying to get the image of the sexy Demonchester out of his head, "But it doesn't matter. It's not like he's better than me. He may be highly dangerous, but for sure, he's not better."

"You shouldn't be so cocky."

"I'm confident. Dean Winchester is nothing special; he's just like all the demons I've been assigned to before."

"Except you fucked this one." Balthazar added, causing Samandriel to giggle.

"Can you not?" Castiel glared at his friend. If this was how friendships were like, he didn't want another one. "I've been having a bad day and I really don't need your sense of humor to help my case."

"What you need is for Demonchester to teach you a lesson on bed again don't you?" This time, his joke made Samandriel burst out laughing.

"I will shoot you."

"C'mon, Cassie, laugh about this a little! Tell me, was he good at it or did he suck?"

"That's none of your concern."

"So he sucked?"

"I never said that."

"He was good?"

"Balthazar!"

Balthazar laughed, "He _was_ good in bed!"

"Isn't he supposed to be? I mean, he is a demon…"

"Samandriel!"

"Leave him alone, I like this kid. So, from a scale from one to ten how good did he take you?"

"I refuse to answer that." Castiel crossed his arm, now irritated by his friend's curiosity. "That's none of your business."

"I'm you friend, of course it's my business."

"Not this time." Castiel ran his hand through his hair again, trying to erase the memories of Dean's hand running up his leg, of his lips on his neck, of his apple green eyes burning deep into his. No, he shouldn't be thinking of what his mission did to him, but how could he not, when it had been _so damn good_! If any angel were to find out about how sinful he had been with the Demon Winchester, they'd all have a whole new perspective of him and lose respect.

Balthazar chuckled when he saw his friend thinking, he knew it was about Dean, "You're going to give me details about how it went, Cassie, this story is interesting."


	3. One More Night

**One More Night**

"_**One More Night" by Maroon 5**_

_You and I go hard at each other like we're going to war._

_You and I go rough, we keep throwing things and slamming the door._

_You and I get so damn dysfunctional, we stopped keeping score._

_You and I get sick, yeah, I know that we can't do this no more._

_But baby there you go again, there you again, making me love you._

_Yeah, I stopped using my head, using my head, let it all go._

_Got you stuck on my body, on my body like a tattoo._

_And now I'm feeling stupid, feeling stupid, crawling back to you._

Castiel made sure that every file on Dean Winchester was on his desk. He needed to know everything there was on that damn man and what made him so special in comparison compared to the other demons.

He was impressed to see how big the stack was. He must've been some kind of high danger that it created such a large history under his name.

He made sure —well, more like threatened— that every angel in the tech department searched for all and any info on the extremely attractive demon. He needed to know his target well before he went out to hunt.

It shocked Cas to know how much Dean had written on his record. At sixteen he was arrested for stealing, at seventeen he dropped out of high school, at twenty-seven he was arrested and taken to jail but was only there for a few days and at twenty-nine, he had become a demon.

Dean had a younger brother, Sam Winchester, who Cas assumed was the white sheep of the family because, according to his file, he was a good, straight A student that was at Stanford before he mysteriously got out.

Suddenly, there was a knock on the door the interrupted Castiel's reading. "Come in." He said, quickly looking up to see who was waiting for his response on the other side of his door. It was his friend Gadreel. He was an angel that clearly wanted to be a hit man but was placed in the office to do other useless tasks. Not many people liked him, but Castiel accepted him.

"So, you and Dean Winchester, huh?" A mocking smile spread across his face.

_Balthazar_, "I'm going to kill him." How dare he betray him like that? How could he go around and just tell people what happened?

"You should be glad I'm the only one Balthazar told, be happy Gabriel hasn't found out yet."

He had a point, Gabriel was not the person you'd want to tell a secret to, "Yeah, but how long before that boundary disappears?"

"He's your friend."

"Not at the moment, that…" he thought about a slang word that the humans used to insult someone, "_Assbutt_." Yes, that seemed appropriate but Castiel was more than sure that it wasn't even a word.

Gadreel chuckled, "When are you going to kill him?"

Castiel set the folder he had been holding aside then stood up, "Let's hope today." He reached for his trench coat, "Is Samandriel ready?" Samandriel was supposed to accompany Castiel in case they bumped into Dean. He was to learn the methods Castiel used before he was sent out on the field for the first time.

"He should be."

"Then please call him over and tell him to take his stuff." Castiel put on his coat before he grabbed his vibrating cell phone. "We're going to have coffee."

**-.-.-.-.-.-**

"**Do you see him?" **Sam asked through the phone. Dean was on top of a five story building that gave him the perfect sight to where Castiel was supposed to be having coffee at.

"I haven't even placed myself, dude." He paused, "Instead of going with Jess you should've come over here to help me." Dean complained as he placed the silver briefcase he had been carrying on top of a wooden box. "Are you sure he has coffee here every afternoon?"

"From what Meg and Ruby have told me? Yeah."

"And you're going to believe what they say?"

"They've been in your position. Except, of course, they didn't bang the guy—" Dean hung up before Sam could finish. He didn't need to be reminded of his mistake. Sometimes, really, it didn't feel like much of mistake to him. Dean _liked_ the sex with Cas. It was great; he wasn't going to deny that.

He started putting together the pieces of the sniper together and placed it on top of the crate to point it at the entrance of the café. At some point, Castiel had to come out if he was there.

Before he had come out there, Dean had searched up Castiel's file and he had to admit that he surprised at what he saw. The guy was good at what he did. Thirty clean deaths for the past six years since he began and was quickly promoted to a higher position amongst the angel assassins.

"C'mon, angel, where are you?" Dean was starting to get impatient. Castiel probably knew that he was after him and decided to miss his daily coffee break knowing that Dean was waiting for him.

That was when his 'Eye of the Tiger' ringtone went off in his pocket. He pulled it out to see who could've possibly been calling him. _Sammy._ "What happened now?"

"Well, it's good to hear about you again, Dean." It wasn't Sam. Abort!

"Castiel, right?" What a way to cover up his shock by pretending to not know the angel's name. "What do you want?"

"Oh, nothing, I'm just having some coffee. Thought I should've checked up on you…"

Dean looked over to the café, even if his sight was slightly blurry, he could make out the tanned trench coat and the messy dark hair that he loved running his fingers through. Castiel noticed him too because, while sitting down, he waved towards Dean's direction. The bastard knew about Dean all along. "You look good in a suit." Dean complimented.

"You don't look so bad in a black shirt." Dean could feel Castiel giving him a gorgeous, yet mischievous smile. That son of a bitch. "Do you have any idea of what I am?"

Castiel nodded and took a sip from his coffee, "Yeah, but do _you_ know what _I_ am?" Of course he knew. It was the third time Castiel had been assigned to a demon hit man. The first two times were failed because this angel genius had caught them and eliminated before they could get anything against him. Castiel was good at what he did; Dean had heard that more times than he needed.

"I suggest that you lower your guns now, Dean." Castiel grabbed a piece of the freshly baked blueberry muffin and took a bite out of it.

"What makes you think I'd listen to you?"

Castiel's tone darkened, "Because I'd hate to abruptly end this call."

Dean smirked, "You can't do shit to me."

"Well, maybe not _me_ at the moment, but maybe my apprentice can."

"What?"

"You know," Castiel paused to take another sip of his coffee, "I never noticed the red spot on your forehead."

"You're a coward…"

"Oh?"

"You have to get your apprentice to get me? Really? You couldn't have been more traditional and done it yourself?"

Cas smiled, finally moving up his blue eyes to the hit man that was aiming his gun on top of the building in front of the café. "If I had done it, we wouldn't be having this conversation…" Even if Dean was really well hidden, Castiel still knew where he was. He was imagining him too. That gorgeous man of six-feet-one with amazing green eyes that could melt anyone that stared into them, pointing his weapon at Castiel.

Ugh, if only their difference didn't get in the way…Cas would've had so much fun with him. He could only imagine what other abilities Dean had in intimacy.

_No, _he thought, _that is highly inappropriate. He's your target, Castiel, don't you ever forget that. _

It was easy to forget, of course, with a mission that looked like that? Oh, Cas only wished he were something else rather than the person he was assigned to kill.

"You're sounding a bit cocky, sweetie; it sounds hot on you."

"Thank you, but words like those won't make tell my apprentice to put his gun down."

Dean chuckled, "I wasn't counting on that."

Dean knew that he wasn't gonna get anywhere with Castiel. There was a fifty-fifty chance of him not shooting Castiel because if he did, he would have a bullet in his head before he could make a small movement. There was no getting out of this one. He knew he should've brought a companion just in case.

Both men were stuck in the situation; there was no way to get out of this one. Neither wanted to shoot and they didn't understand why. If it had been with any other mission, they would've been done in a day or less so why had things changed this time? What hid underneath all that hate that they claimed to have for each other that prevented Dean pulling the trigger, and Castiel from saying the words to Samandriel?


End file.
